SEATTLE – Addressing 275 of the world’s most brilliant scientists, Bill Gates cracked a joke: “I’ve been applying my imagination to the synergies of this,” he said. “We could have sorghum that cures latent tuberculosis. We could have mosquitoes that spread vitamin A. And most important, we could have bananas that never need to be kept cold.” They laughed. Perhaps that was to be expected when the world’s richest man, who had just promised them $450 million, was delivering a punchline. But it was also germane, because they were gathered to celebrate some of the oddest-sounding projects in the history of science.